Abstract: A snap lock for securing to a sash of a sliding window or door by interacting with a striking plate and for securing to a frame of the sliding window or door. The snap lock comprises stationary lower and upper plates for sandwiching a rectilinearly mobile plate for locking the snap lock with respect to the striking plate. The snap lock includes as well: a three-point pivoting mechanism for interconnecting the foregoing plates to perform an unlocking operation; a springy feature for keeping, when relieved from tension, the rectilinearly mobile plate in an unlocked, retracted position, and when under tension, for keeping the rectilinearly mobile plate in a locked position, the springy feature being attached to the stationary lower and upper plates and being actuated by a contact with the striking plate; and a cover having an aperture for locating and accessing a button for acting upon the three-point pivoting mechanism.

Abstract: The device comprises a housing encasing a pair of upper and lower hooks, for counter-rotational movements; a pair of upper and lower adjusting assemblies, vertically spaced in parallel with the pair of upper and lower hooks for positioning the latter within the housing; an actuating assembly including a double-armed pivot having a cylindrical body and a pair of radially extending arms, disposed between the pair of upper and lower hooks; and a pair of upper and lower connecting links, mounted between the double-armed pivot and the pair of upper and lower hooks. Upper and lower connecting links are different, to accommodate the cylindrical body, in all the positions of the hooks. The upper connecting link can partially wrap around, the cylindrical body. The lower connecting link can partially wrap around, the cylindrical body.